chore(deps): bump @grpc/grpc-js from 1.8.19 to 1.8.20 in /proto (#1384)

Bumps [@grpc/grpc-js](https://github.com/grpc/grpc-node) from 1.8.19 to 1.8.20.
- [Release notes](https://github.com/grpc/grpc-node/releases)
- [Commits](https://github.com/grpc/grpc-node/compare/@grpc/grpc-js@1.8.19...@grpc/grpc-js@1.8.20)

---
updated-dependencies:
- dependency-name: "@grpc/grpc-js"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

proto/package.json

@@ -6,7 +6,7 @@
   "bugs": "https://github.com/ory/keto/issues",
   "main": "./index.js",
   "dependencies": {
-    "@grpc/grpc-js": "1.8.19",
+    "@grpc/grpc-js": "1.8.20",
     "google-protobuf": "^3.21.2"
   }
 }